A leaning tree is common, especially among newly planted specimens whose root systems are still establishing themselves. The lean is often correctable with the right approach and equipment. Successfully correcting a lean depends on accurately diagnosing the cause and applying a technique appropriate for the tree’s size and age, allowing it to develop a strong, structurally sound trunk and root system.
Assessing the Lean: Determining Feasibility and Cause
The first step in addressing a leaning tree is determining if the problem is fixable without professional machinery. If a tree’s trunk diameter exceeds four inches, or if it has been established for several years, attempting to straighten it without consulting an arborist can be dangerous. Trees that have been leaning for a long time develop structural changes, such as reactionary wood, that make correction difficult and risky.
Leaning often results from common issues, including improper planting depth or poorly compacted soil that fails to anchor the root ball firmly. Prevailing winds can push a young tree persistently in one direction, or the tree may be exhibiting phototropism, growing toward a stronger light source. A sudden, severe lean, especially after a storm, can indicate root plate failure, where the roots have lifted out of the soil, necessitating immediate intervention to prevent the tree from falling over.
Step-by-Step Guide to Staking Young Trees
Staking is the appropriate solution for young trees, typically those under four inches in diameter, whose root ball still shifts when the trunk is gently moved. Use two or three sturdy stakes (wood or metal), a sledgehammer, and a wide, flexible tie material, such as tree webbing or a soft strap. Avoid using thin wire or rope, as these materials can easily cut into and damage the bark.
Drive two or three stakes into the ground just outside the perimeter of the root ball, positioning them to counteract the lean or the prevailing wind. The stakes should be driven 18 inches or more into the soil for stability. Gently push the tree upright, taking care not to damage the fragile roots; this is easier if the surrounding soil is moist.
Attach the tree to the stakes using the flexible tie material, securing it one-third to two-thirds of the way up the trunk. This height allows the top of the tree to move naturally in the wind, which stimulates the trunk to grow stronger. The ties should be loose enough to allow slight movement but firm enough to hold the trunk in its new vertical position.
Stabilization Techniques for Moderately Sized Trees
When simple staking is inadequate for a larger transplanted tree or one with a more established lean, a guying system provides the necessary robust support. Guying involves using three cables or ropes anchored to points further away from the trunk. This method is often reserved for trees with a trunk caliper of four inches or more.
The guying wires or ropes should be attached to the tree using a non-abrasive material, such as rubber hose or a wide nylon strap, to protect the bark from girdling or rubbing. The three anchor points, typically stout wooden stakes or specialized subterranean anchors, should be driven into the ground at an equal distance around the tree. The cables should be attached to the trunk, ideally at a 45- to 60-degree angle from the ground for maximum leverage and stability.
Subterranean anchor kits offer a discreet solution, using strong cables attached to anchors driven deep into the ground. These systems are useful in high-traffic areas where exposed stakes or wires could be a tripping hazard. For both guying and subterranean anchoring, the tree should be pulled back to a vertical position using a hand winch or mechanical advantage before the cables are tightened to provide firm, but not rigid, support.
Post-Correction Monitoring and Support Removal
Regular monitoring is necessary to ensure the hardware is not causing damage. The tree ties and cables must be checked monthly, especially during periods of rapid growth, to confirm they are not cutting into the expanding trunk or branches. This condition, called girdling, interrupts the flow of nutrients and water just beneath the bark and can ultimately kill the tree if left uncorrected.
The support system should remain in place for a minimum of one full growing season. This duration allows the tree’s root system to anchor itself firmly in the new position. Once this period has passed, the supports must be removed completely; leaving the hardware in place for too long can inhibit the tree’s natural trunk taper and result in a weaker tree.